Tailstock



gAug. 29, 1944. R. E. FLANERS TAILSTOCK Filed Aug. 26, 1941 `5Sheets-Sheet l a cru-1u 5 Sheets-Sheet 2 frz/M2271? f, f

JM mwlauw R. E. FLANDERS TAILSTOCK Filed Aug. 26, 1941 Aug. 29, 1944.

Aug. 29, 1944.

R. E. FLANDERS TAILSTOCK Filedk Aug. 26, -1941 s sheets-sheet 5'Patented Aug. 29, 1944 UNITED STAT NT OFFICE TAILSTOCK ApplicationAugust 26,1941, Serial No. 408,368

14 Claims. (QI. 51-237) This invention relates to machine tailstocks forsupporting one end portion of work, the other end portion of which issupported for rotation in a headstock.

One kof the objects of this invention is to provide a tailstock having awork `spindle for supporting the tailstock end of the work, this spindlebeing axially movable relative to the tailstock, the tailstock alsobeing adjustable on the bed of the machine in the same direction as theaxial movement of the spindle- A further object of the invention is toprovide a mounting for the tailstock center within the spindle forlimited yielding axial motion and to provide for lateral motion of thework engaging portion of the center to provide for relief on the landswhere uted work such as a tap or reamer is being held by the machine forgrinding or other machining operations to be performed thereon.

Still another object is to provide novel and improved means forproducing such` relieving motion in time with the rotation of the flutedWork.

For a more complete understanding of this invention, together with otherobjects and advantages, reference may be had to the accompanyingdrawings in which Figure 1 is a fragmentary front elevation of a lgrinding machine embodying the invention.

Figure 2 is a fragmentary top plan view of the same.

Figure 3 is a partial left hand elevation of the same partly brokenaway.

Figure 4 is a detail section on line 4 4- of Figure 3.

Figures 5, 6 and 7 are detail sectional views on the correspondinglynumbered section lines of Figure 4.

Figures 8 and 9 are diagrammatic views'illustrating the relationshipbetween right andv left hand taps, respectively, adjustments ofindicating means and the relief cam when starting grinding of the taplands.

Referring to Figures 1 and 2, at I is indicated a machine base providedwith longitudinally extendingways upon which are mounted a headstock 3and a tailstock 4, adjustable along the Ways. In order to so adjust thetailstock the bed is provided with a rack bar 6 and the tailstock isprovided with a pinion 8 meshing with the rack `bar 6 and supportedWithin a casing |0 secured to the tailstock. A squared shaft I Icarrying the pinion 8 extends outwardly for the reception of' a wrenchor handle by which it may and the corresponding be turned to adjust thetailstock axially as may be desired. The tailstock justed position byany suitable means (not shown) as is well known in the art.

The headstock 3 may be similarly adjusted and secured, as shown in myapplication for patent Serial No. 353,050, filed August 17, 1940, forGrinding machine, of which the present application is a continuation inpart. As shown in the parent application the headstock is provided withan axially movable spindle I5 carrying a work holding face plate I6 andthis spindle is moved axially as through a lead screw 29 and acooperating xed nut -40 having the same lead as the work to be operatedupon, which is shown as a tap 35, the threads of which are to be groundby the grinding wheel 3 6. The axial motion of the work spindle as it isrotated with the lead screw, is caused to produce a like axial motion ofthe tailstock spindle 5 relative to the tailstock. This is done bysuitable operative connections from the headstock spindle to an axiallymovable bar |05 which extends into the tailstock casing as through asuitable packing gland at |01. This connection includes a yoke member|0| fixed to the bar |05 and straddling a bearing member 99 carried by agear l94 secured to the spindle. The spindle is rotated through the gear94 -by a suitably driven long gear 03. The rear end rof the bar |05 isformed as a rack bar and slidable on this bar |05 at the rack portion isa casing ||0 (see Figures 1, 2 and 3). This casing has a rearwardextension through which is passed a bolt 2 extending througha slot I I3in a cap H4 (see Figures 2 and 4) which houses the rear end of atailstock spindle ||5 slidably but non-rotatably mounted in thetailstock 4. IlMeans are provided for clamping the casing end the casing||0 is provided with a rock shaft |20 on which is jourmeshes with theteeth may be secured in ad- This rock shaft |20 has,I |22 and betweenthe ring to an arm |26, the outer end of which carries a spring latchpin |21 which may be engaged in a latch pin socket |28 in a face plate|29 carried by the casing ||0. This latch may -be released from itssocket by pulling outwardly on a handle |30 fulcrumed at |3| on the rockshaft |20 and through which a shank |32 of the latch pin |21 projects,this shank having a head |34 on its forward end. By pulling outwardly onthe handle |30 the latch pin may be retracted from its socket |28 andthen by rocking this handle to the right as viewed in Figure 1 about theaxis of the shaft |20, the shaft |20 may be turned, thus turning thepinion |2| and producing a corresponding retraction of the tailstockspindle. This provides for retracting the tailstock spindle for theremoval and insertion of work between the spindles. In the normaloperative condition the handle is in the position shown in Figure l andis latched in this position, in which position also the head andtailstock spindles are connected to the rack -bar for simultaneous andequal axial motion, thus carrying the work 35 and effecting thelengthwise traverse of it with relation to the grinding wheel 36.

The tailstock spindle carries the cone center |40, which as shown inFigure 4, is carried by a tailstock center block |4|. In grinding a tapit is desirable that the lands of thetap be relieved in order to provideclearance back of the cutting edges of the tap, and for this purpose amotion of the tap from and toward the grinding wheel in time with therotation of the tap is provided. As shown this relief is produced by amotion of the tailstock center. To this end the center block |4| isrockably mounted in the forward end of a sleeve |42 slidable axiallywithin' the tailstock spindle I5. This sleeve |42 is keyed to thespindle ||5, for this purpose a screw plug |43 being provided which isthreaded into a side wall of the spindle ||5 and has a reduced extremity|44 riding in a slot |45 in the sleeve |42. The shank |48 of the centerblock |4| extends rearwardly in the sleeve |42 and through a slot |41 inits rear end. To the rear of this sleeve |42 is positioned a coilspring"|48 which reacts between the rear end of this sleeve and atransverse partition |49 of the spindle ||5, this acting to press thesleeve |42 forwardly and carrying with it the center |40 so as to holdthe work snugly between the head and tailstock centers. A second spring|480, also surrounding the shank |46, bears at one end against the rearend of the sleeve |42 and against a collar |48| engaging a transversepin |482 extending through the shank |46. This spring |480 holds thecenter block |4| with its concave rear face into enga-gement with theforward end of the sleeve |42, while permitting rocking motion of theblock |4 The tailstock center is arranged to be rocked about its bearingagainst the end of the sleeve |42 to produce the relieving action.

To prevent the entrance of coolant and foreign matter into thetailstock, a conical flexible shield |50 is secured at its forward endto the center block |4| Yand to its rear end to a boss |5| of thetailstock.

The rear end of the shank |46 is split as at |55 and has a threadedopening |56 to receive a screw |51 (Figures 6 and 1) provided with ahead |58 which screw extends through a slot |59 through the spindle ||5.On the forward end of the screw |51 is threaded a sleeve |60 having aknurled head |6| at its forward end.

This sleeve |60, asshown in Figure 6, is secured to the screw |51 as bya cotter pin |62. The split ends |55 are clamped together as by thethumb screw .|65 which extends through a slot |66 in the top of thespindle ||5 so that it may be accessible for actuation to clamp orrelease the screw |51. By adjustment of the screw |51 the tailstockcenter may be adjusted laterally for parallel or tapered work as may bedesired. In the case of taps it is common practice to provide for taperwith the end diameter larger so that all of the cutting is done by thefirst few teeth.

The head |58 is pressed by a spring |64 againstthe face of the lever |10pivoted between a pair of centers |1| fixed in a pair of oppositelydisposed ears |12 of a slide |13. This slide, as best shown in Figure 6,is mounted for vertical sliding movement in a guideway |14 in the rearwall of the tailstock 4 and it may be vertically adjusted by means of ascrew |15 threaded thereinto and provided with a head |16 positioned ina recess |11 in a block |18. This block |18 is secured to the rear wallof the casing 4, as by means of a screw |19. The cover of the tailstockcasing is provided with an opening |8| in substantial alinement with thehead |18 and through which this head is accessible to a screwdriver inorder to adjust the slide |13 vertically. This adjustment determines theeffective amplitude of motion of the head |58 and thus of the deadcenter |40 for the relieving action for a given amplitude of swingingmotion of the lever |10.

When the axis of the centers |1| is in axial alinement with the head|58, swinging motion of the lever |10 is ineffective to oscillate thecenter block |4| and the center |40, but as the slide |13 is movedupwardly, the amplitude of this relieving motion of the center |40 isincreased. The lower end of the lever |10 is formed as a narroweddepending tail (see Figures 4 and 6) tothe lower end of which is secureda U shaped guide |86 between the sides of which is'positioned aneccentric |81 forv bearing von opposed walls thereof. This eccentric |81is secured to the forward extremity of a stub shaft |88 which is .pinnedto and within a sleeve |89. This sleeve isjournaled in bearings |90 and|9| and is held in axial position by a nut |92 on one side of thebearing |9| which holds this against an annular shoulder |93 of thesleeve |89.

Keyed for longitudinal but non-rotative motion relative to the sleeve|89 is a shaft |94. This shaft |94 extends into a change gear casing|950 at the tailstock end of the machine (see Figures 1, 2. and 3). Onthe splined end of this shaft |94 is a gear |95, and clamped to a boss|96 through which the shaft |94 passes is a hanger |91 having a slottedarm |98 for the reception of a stub shaft |99. This stub shaft carriesthe change gears 200 and 20|, the gear 20| meshing with the gear |95 andthe gear 200 meshing with a gear 202 on the splined rear end of theshaft 90. A hinged cover 203 provides access to this train of gearsl sothat the speed ratio between the shafts |94 and 90 may be adjusted asdesired. Thus for each revolution of the drive shaft 90 and consequentlyrotation of the work spindle, the correct number of oscillations of thedead center |40 may be produced depending upon the number of flutes inthe tap being ground and thus produce a relief on each of the landsbetween the flutes.

In order to properly relate the direction of relief for right and lefthand taps, provision is made for indicating the correctan-gularposition.

y the turning of the shaft of the cam |81 when a. cutting edge of thetap is in the plane of the work and Wheel centers. To'

this end the sleeve |89 is-provided with a pointer |890 which may beturned into registry with the proper mark R or L, angularly spaced, ona'ring member |89| secured as by screws to the tailstock of the machine.This adjustment for right or left hand taps may be done only-when thechange gears 200 and 20| are out of mesh with one or both of theirmating gears, as it requires |94 to which the sleeve |89 is keyedrelative to the shaft 90.

In setting up for a right hand tap, for example, the slide |13 isadjusted so that the pivots |1| are opposite to the center of the screw|51, in which position the top of the slidev |13 isv opposite the zeroindication on the scale 205' (Figure 4). Thus adjusted, the grindingwill be concentric and with or without taper, depending on the settingof the screw |51. The machine can then be adjusted so that the top isautomatically sized to the proper diameter. Then the top is adjustedangularly to bring a cutting face to a predetermined angular position(which may be determined by any suitable gaging means not shown) anddogged in that position. The sleeve |89 is then adjusted to bring thepointer at |890 in line with the letter R and the change to the positionto give the desired eccentricity for relief. The extent of eccentricityis determined by the setting ofvthe slide |13, while the start of theoscillation producing the eccentricity is determined by the setting ofthe screw |51. Each succeeding tap is dogged when in the same angularposition of a cutting edge.

In grinding taps it is better practice to have the wheel first contactat the cutting edge of each land. This is for the reason that whencutting the Width of the land the heat increases and faster grindingwithout injury by over-heating the cutting edge is then possible.Therefore the direction of rotation of the tap is reversed when grindingleft hand taps, the direction for right and left hand taps beingindicated by the arrows a and a', respectively, in Figures 8 and 9.Since the relieving cam |81 is geared to the work spindle, the directionof rotation of this cam is also reverse in accordance with the arrows band b', respectively, of Figures 8 and 9. This cam turns one revolutionwhile the tap is turning the angular distance of one land and one flute,and when grinding the land uses that part of its rotation from A to B.If, when the top is set with a cutting edge on a plane coincident withthe axes' of the tap and grinding wheel and the quill |89 is set so thatthe pointer |890 is opposite to the letter R forright hand taps, asshown in Figure 8, or opposite to Ythe letter L for left hand taps, asshown in Figure 9, the lever |10 is in vertical position in line withthe direction of adjustment of its fulcrum for controlling the amount ofrelief. Any adjustment of the lever vertically as by turning the screwwill not change the eifective diameter of the tap. It is thereforepossible, having adjusted the machine to grind the proper diameter tovary the amount of relief without varying the diameter since variationof the relief does not vary the starting point of grinding at thecutting edges of the lands which lead in the direction of rotation ofthe work.

A grinding Wheel 36 is suitably supported on a traversing movablecarriage on the work bed I, as, for example, as shown in my Patent No.2,187,227 hereinbefore mentioned, and this grindgears are then broughtinto mesh. The slide |13 is then movedv s motion substantially 40` ingwheel mayr be driven from a motor 31 as through a belt drive 30 as alsoshown in my patent.

From the foregoing description of an embodiment of this invention, itshould be evident -to those skilled in the art that various changes andmodications might be made Without departing from the spirit or scope ofthis invention as dened by the appended claims.

I claim:

1. In combination, a machine bed, a tailstoek carried by said bed, meansforxing said tailstock to said bed, a work supporting spindle mountedfor axial motion in said tailstock, an axially movable bar mountedsubstantially parallel With the axis of said spindle, means for lockingsaid spindle and bar together for simultaneous axial motion, a workengaging center block axially movable with respect to said spindle, andyielding means tending to hold said block at an outer limit of suchaxial motion.

2. In combination, a machine bed, a tailstock carried by said bed, meansfor fixing said tailstock to said bed, a work supporting spindle mountedfor axial motion in said tailstock, an axially movable bar mountedsubstantially parallel with the axis of said spindle, and meansconnecting said spindle and bar together for simultaneous axial motionand including mechanism actuable to move said spindle axially withrespect to said bar, a work engaging center block axially movable withrespect to said spindle, and yielding means tending to hold said blockat an outer limit of such axial motion.

3. In combination, a work supporting spindle, a stock supporting saidspindle for axial motion relative to said stock, means for moving saidspindle axially comprising a rack bar mounted for parallel to the axisof said spindle and relative to said stock, means for moving saidrack'bar axially, and means engageable with the teeth of said rack barand operatively connected to said spindle causing motion of said rackbar relative to said stock to move said spindle relative to said stock.

4. In combination, a work supporting spindle, means supporting saidspindle for axial motion, means for moving said spindle axiallycomprising a rack bar mounted for motion substantially parallel to theaxis of said spindle, means for moving said rack bar axially, a casingslidable axially of said rack bar and connected to said spindle, a shaftjournaled in said casing, a pinion fric'tionally attached to said shaftand meshing with the teeth of said rack bar, an actuating handle-carriedby said shaft, and a latch for releasably holding said handle in apredetermined angular position.

5. In combination, a hollow spindle, means supporting said spindle foraxial motion, a sleeve axially slidable within -said spindle, a springvbearing on said sleeve and yieldingly pressing said sleeve toward anouter limit of axial motion, a center block rockably supported by saidsleeve at vthe outer end of said sleeve and having a shank extendinginwardly thereof, a member carried b-y said shank and extending througha slot in said spindle, means for moving said spindle axially, and meansengaging said member for rocking said center block.

6. In combination, a center block having a shank, means supporting saidblock for rocking motion about an axis transverse to said shank, a conecenter carried by said block, a lever, operative `connections from saidlever to said shank, means for rocking said lever thereby rocking saidcenter block and oscillating said center, and means for moving saidlever to adjust the fulcrum of said lever relative to saidoperative-connections to thereby vary the amplitude of motion of saidcenter for a given amplitude of rocking of said lever.

'7. In combination, ya work center, means supporting said work centerfor motion about a transverse pivot laterally of its axis, means forproducing such lateral motion comprising a lever, operative connectionsbetween said lever and center at one side of said pivot to cause rockingrof said lever to produce lateral motion of said center, means ofconstant stroke for rocking said lever, and means for moving said levertoadjust the relation of its fulcrum to said operative 'connections tothereby adjust the amplitude of motion of said work center.

8. In combination, a machine bed, means including a tailstockforsupporting fluted Work for rotation, a work engaging element carriedby said tailstock, means for oscillating said Work engaging element intime with the rotation of the work to provide relief for the landsbetween the flutes of said work by a tool presented to the work duringits rotation, said oscillating means including a cam, and adjacentdriving parts marked to indicate adjustment of said cam to adjust theangular direction of relief in accordance with whether the work is rightor left hand.

9. In combination, a machine bed, means in'- cluding a tailstock forsupporting fluted work for rotation, a work engaging element carried bysaid tailstock, means for oscillating said work engaging element in timewith the rotation of the work to provide relief for the lands betweenthe flutes of said work by a tool presented to the work during itsrotation, said oscillating means including connections including aleverrockable to oscillate said element, a rotary. cam engaging said lever toeffect such oscillation, and means for rotating said cam once for eachcomplete oscillation, said rotating means having adjacent driving partsmarked for adjustment of said cam angularly to determine the directionof oscillation while the lands between the flutes of the work are beingoperated upon by the tool, to thereby determine the angular direction ofthe relief in accordance with whether the work is right or left hand.

10. In combination, a machine bed, means including a ta'ilstock :forsupporting iluted work for rotation, a work engaging element carried bysaid tailstock, means for oscillating said work engaging element in timewith the rotation of the work to provide relief for the lands betweenthe flutes of said work by a tool presented to the work during itsrotation, said oscillating means including connections including `alever rockable to oscillate said element, a rotary cam engaging saidlever to effect such oscillation, and means for rotating said cam oncefor each complete oscillation, said means having parts marked to showadjustment of said cam angularly with relation to said rotating means tocorrectly reshank portion,

late the oscillation of said lever to produce relief of the lands of thework whether right or left hand.

11. In combination, a work center, means supporting said work center formotion laterally of its axis, means for producing such lateral motioncomprising a lever, operative connections between said lever and centerto cause rocking of said lever to produce lateral motion of said center,a cam operatively engaging said lever, a slide block to which said leveris fulcrumed, means for adjusting said slide block to thereby adjust theposition of said fulcrum with relation to said cam and to said operativeconnections and thereby adjust the amplitude of lateral motion of saidwork center produced by action of said cam, and means for driving saidcam.

12. In combination, a work center, means supporting said work center formotion laterally of its axis, means for producing such lateral motioncomprising a lever, operative connections between said lever and centerto cause rocking of said lever to produce lateral motion of said center,a ycam operatively engaging said lever, a slide block to which saidlever is fulcrumed, a member threaded into said slide block, meanssupporting said threaded member for rotation but against axial motion tocause rotation of said threaded member to move said slide block andadjust the position of said fulcrurn with relation to said cam and tosaid operative connections and thereby adjust the amplitude of lateralmotion of said work center produced by action of said cam, and means fordriving said cam.

13. In combination, a hollow spindle, means supporting said spindle foraxial motion, a sleeve axially slidable within said spindle, a springbearing on said sleeve and yieldingly pressing said sleeve toward anouter limit of axial motion, a center block rockably supported at theouter end of said sleeve and having a shank extending inwardly thereof,a member carried by said shank and extending through a slot in saidspindle, means for moving said spindle axially, means engaging saidmember for rocking said center block, and means for adjusting saidmember with respect to said shank.

14. In combination, a center block having a means supporting said blockfor rocking motion, a cone center carried by said block, a lever,operative connections from said v lever to said shank, means for rockingsaid lever thereby rocking said center block and oscillating saidcenter, means for adjusting the fulcrum of said lever relative to saidoperative connections to thereby vary the amplitude of motion of saidcenter for a given amplitude of rocking of said lever, a rotary drivingmember, connections from said driving member for rocking said lever, andmeans for adjusting said last mentioned connections to adjust the timingof oscillation of said center to either of two denite angular positionsof said driving member suitable for right or left hand fluted work,respectively. RALPH E. FLANDERS. r

